In German Patent Specification No. 2 338 446, there is disclosed an embossing calender for thermoplastics films. Such calender comprises an embossing roller having a relatively small diameter and a counter-roller which has a larger diameter and is covered with a resilient coating. The embossing roller and counter-roller are mounted in a support column which is not shown in the drawings accompanying this prior document.
The embossing rollers used for embossing thermoplastics films or similar materials need to be interchanged at frequent intervals so that, for example, the pattern being embossed can be altered. Similarly the counter-rollers, which are covered with a resilient coating, also need to be interchanged at frequent intervals. In practice, the counter-roller is interchanged approximately five times less frequently than the embossing roller.
The procedure involved in changing the embossing roller and the counter-roller disclosed in the above-identified prior art causes the entire calendering production line being out of operation for a lengthy period of time, since such line generally comprises a processing extruder for the thermoplastics material, the means for feeding the material into a calender, the calender itself, a subsequent stretching and cooling section, an embossing calender and a winding station, such a lengthy period of inactivity is obviously economically undesirable.